Telecommunications.dwf very slow to view

[Anonymous]

In the Freewheel gallery there is a sample DWF that views fine in Freewheel within a few seconds:
http://dwfit.com/dwf.aspx?dwf=http://dwfit.com/sample/Telecommunications.dwf

When I download Telecommunications.dwf to my local machine and view it with the DWF Viewer 7.0.0.928 it is terribly slow: it takes several minutes to fully show.

Why this big difference?
I tried it on Windows 2000 and on Window XP SP2, plenty of GHz and memory.

[Anonymous]

It is a big file with complicated entities. I had already viewed it on the
Freewheel server, so it had a cached copy of the file.
wrote in message news:5267380@discussion.autodesk.com...
In the Freewheel gallery there is a sample DWF that views fine in Freewheel
within a few seconds:
http://dwfit.com/dwf.aspx?dwf=http://dwfit.com/sample/Telecommunications.dwf

When I download Telecommunications.dwf to my local machine and view it with
the DWF Viewer 7.0.0.928 it is terribly slow: it takes several minutes to
fully show.

Why this big difference?
I tried it on Windows 2000 and on Window XP SP2, plenty of GHz and memory.

[Anonymous]

So it is normal that this DWF file stored on my local(!) disk takes several minutes to open?
I do not believe this has anything to do with caching. I examined the DWF file and it holds more that 3000 tiny PNG-images. Apparently the DWF viewer cannot handle those PNG images very well.

[Anonymous]

While the file may have been cached on the server, using the link you
posted, the server still had to open the file, render it to a PNG and
transmit it over the internet. The viewer on the other hand only had to load
and render the file. The big difference is that at this time freewheel does
not load the object data and this file has lots of object data.



Ben



wrote in message news:5267380@discussion.autodesk.com...
In the Freewheel gallery there is a sample DWF that views fine in Freewheel
within a few seconds:
http://dwfit.com/dwf.aspx?dwf=http://dwfit.com/sample/Telecommunications.dwf

When I download Telecommunications.dwf to my local machine and view it with
the DWF Viewer 7.0.0.928 it is terribly slow: it takes several minutes to
fully show.

Why this big difference?
I tried it on Windows 2000 and on Window XP SP2, plenty of GHz and memory.

[Anonymous]

I do not think this has anything to with object data: there isn't any in this DWF. When I extract the W2D file and view it separately it is just as slow.
The extreme delay seems to be caused by the preview-while-rendering. When I open the file and minimize the DWF viewer while it is loading the file, I can see in the taskmanager it is finished loading in about 15 seconds. Restoring the window takes some 5 more seconds and I am up and viewing in 20 seconds, 10 times faster than normal opening.

[Anonymous]

You are correct. I often group object data with hyperlinks because from a
rendering point of view they both populate the selection data structures.
The viewer is spending a lot of time processing all the selectable
hyperlinks. But you are also correct; the incremental loading in the viewer
is defiantly an area for improvement.



When I wrote the renderer/loader used by Freewheel, I removed the overhead
of things like objects, hyperlinks, incremental loading and other things.
The viewer can't simply remove these things, but needs to improve them.

Ben



wrote in message news:5268007@discussion.autodesk.com...
I do not think this has anything to with object data: there isn't any in
this DWF. When I extract the W2D file and view it separately it is just as
slow.
The extreme delay seems to be caused by the preview-while-rendering. When I
open the file and minimize the DWF viewer while it is loading the file, I
can see in the taskmanager it is finished loading in about 15 seconds.
Restoring the window takes some 5 more seconds and I am up and viewing in 20
seconds, 10 times faster than normal opening.

[Anonymous]

I don't want to be nagging 🙂 but I see no hyperlinks in the drawing.
This drawing caught my interest because I had written a serverbased viewer (*very* much like Freewheel) and my viewer was very slow rendering it too.
Mine was slow because I use gdiplus to load and decode the 3310 PNG images and gdiplus was initialized and shutdown 3310 times. When I changed that to only once it became a lot faster.

[Anonymous]

What Ben is trying to point out is that because this dwf has object
properties, each property requires a handle to create the clickable area.
The more objects, the more handles that are needed. Each handle slows the
system down a bit more as its created and redrawn. When you minimize the
viewer during load, it doesn't keep redrawing the handles as they are read
in. Thus, when you take the viewer from it's minimized view after it's done
loading, it draws the handles one last time and it's much faster.

The QA & SWD departments are aware of this performance issue


wrote in message news:5268266@discussion.autodesk.com...
I don't want to be nagging 🙂 but I see no hyperlinks in the drawing.
This drawing caught my interest because I had written a serverbased viewer
(*very* much like Freewheel) and my viewer was very slow rendering it too.
Mine was slow because I use gdiplus to load and decode the 3310 PNG images
and gdiplus was initialized and shutdown 3310 times. When I changed that to
only once it became a lot faster.

[Anonymous]

The core rendering technology in both the viewer and freewheel is the same.
Neither use GDI+ for PNG processing. As you have noticed the performance of
GDI+ is less then stellar and not very scaleable. I would recommend you look
at libpng http://www.libpng.org/pub/png/. It is the industry standard for
reading and writing PNG.



Ben



wrote in message news:5268266@discussion.autodesk.com...
I don't want to be nagging 🙂 but I see no hyperlinks in the drawing.
This drawing caught my interest because I had written a serverbased viewer
(*very* much like Freewheel) and my viewer was very slow rendering it too.
Mine was slow because I use gdiplus to load and decode the 3310 PNG images
and gdiplus was initialized and shutdown 3310 times. When I changed that to
only once it became a lot faster.

[Anonymous]

Thanks for the tip. The production version of my renderer uses the CxImage library that internally indeed uses libpng.
I was just looking for ways to reduce the size and complexity of my application by replacing CxImage with the Microsoft GDIPlus. It is working now and I got the performance to be the same but I may drop GDIPlus as I just don't trust a service (IIS) to access an application that uses GDIPlus.

[Anonymous]

Depending on how you use it, calling GDI is not necessarily a bad thing. It
just depends on what you are using it for.



I am interested in how you use your product. Is this an intranet or Internet
solution?




Ben




wrote in message news:5269464@discussion.autodesk.com...
Thanks for the tip. The production version of my renderer uses the CxImage
library that internally indeed uses libpng.
I was just looking for ways to reduce the size and complexity of my
application by replacing CxImage with the Microsoft GDIPlus. It is working
now and I got the performance to be the same but I may drop GDIPlus as I
just don't trust a service (IIS) to access an application that uses GDIPlus.

[Anonymous]

It is more a gut feeling why I do not like GDI Plus. It might indeed work very stable.

I sent you an e-mail with info on my viewer application.